Siemens SIPROTEC 5 Manual page 482

Glossary
Pst (Perceptibility, short-term)
Short-term flicker strength according to IEC 61000-4-15
Rapid Spanning Tree Protocol
The Rapid Spanning Tree Protocol (RSTP) is a standardized redundancy process with a short response time. In
the Spanning Tree Protocol (STP protocol), structuring times in the multidigit second range apply in the case of
a reorganization of the network structure. These times are reduced to several 100 milliseconds for RSTP.
Real Time
Real time
Reorganize
The frequent addition and deletion of objects results in memory areas which are no longer used. The reorgani-
zation of projects allows these memory areas to be freed up again. The reorganization also leads to VD
addresses being reassigned. This results in all SIPROTEC devices having to be reinitialized.
RSTP
See Rapid Spanning Tree Protocol.
Sampling rate
The sampling rate describes the number of samples taken per period. For protection applications, typical
sampling rates are between 16 and 80. A widely used value is 20 samples per period For power quality appli-
cations, the sampling rate must be considerably higher because of the evaluation of harmonics. A typical value
is 256. If sampling-frequency tracking is used, a constant sampling rate per current power frequency period
can always be assumed regardless of the current power frequency.
SBO
Select before operate
SC
See Single Command
SC
See Single Command
SCD
See Substation Configuration Description
SDHC
Secure Digital High Capacity
Standard for SD memory cards with up to 32 GB capacitance
Service Interface
Device interface for interfacing DIGSI 5 (for example, through a modem)
SI
See Single-Point Indication.
482 SIPROTEC 5, Fault Recorder, Manual
C53000-G5040-C018-5, Edition 11.2017